Veneering press



March 28, 1939. H. WIEDERKEHR 2,151,880 VENEERING PRESS` Filed March 25,1957 2 sheets-sheet l fs 24 ,2+ la -23 4 2a i 9 i H Il I/ 20. '7 4 5 2f1 11 12 1o L a3 l ff Mmmm March 28, 1939... H. WIEDERKEHR 2,151,880'

' VENEERING PRESS Filed Marchk 23, 1957 v 2 sheets-sheet 2 f4 7 is f4 "2v 'Janna/mad,

Patented Mar. 28, 1939 UNITED STATES` PATENT oFElcE VENEERING PRESS landApplication March 23, 1937, Serial N0. 132,650 in Switzerland July 31,1936 1 Claim- The present invention relates to aveneering pressparticularly for irregular surfaces and relates to that kind of presses,where the veneer is applied by means of a iiexible, impermeable cover 6vput under hydraulic or pneumatic pressure con-` tained in a hoodcovering the work piece.

The invention consists in lmechanical means for lifting off said hoodand in means for heating A cut oif valve 22 controls the feeding of thecylinders I5 with compressed air and an air relieve 10 the tablereceiving the work piece. l The annexed drawings represent oneembodiment of the invention. 'I'here is:

Fig. 1 a cross section, Fig. 2 a longitudinal section, Fig. 3 a diagramof the pressure gas conduit l and Fig. 4 a detail of the connectionbetween pressure gas conduit and inlet of the hood.

According to Figures 1 and 2 a rectangular .25 to a power currentsystem. Plate 4 is coated on its upper side with a heat insulating layer5 and table plate 2 has a grooved ledge 6 running all around its bordersinto which t the bulbed edges of a hood l of semi-circular cross sectionclamping .fast thereby a flexible impermeable cloth 8,

preferably of rubber, which closes the open bottom of said hood. Theedges of the cloth -projected to the outside of the hood are suspendedthere by means of helical springs 9.

As means for lifting the hood from the table plate guide pieces I9 areattached to its two ends. A

Said guide pieces are guided in verticalguide rai-ls I8 fast to thetable plate and are controlled by piston rods I'l the pistons I6 ofwhich are fitted 40 to vertical cylinders I5 attached to the stand I.The piston rods are formed as racks meshing with pinions 20 fast to rail2I for the purpose of securing the parallel 'displacing of said guidepieces. Pins 23 secured to these guide pieces are adapted to be caughtby hooks 24 hinged to the ends of said guide rails When the hood hasbeen lifted into its uppermost position. This prevents any accident tothe workmen. Before lowering the hood again said hooks must be pushedaside by hand. l

In the hollow space of the stand and underneath plate 4 a devicefor-producing compressed and heated air is arranged on a bracket of saidstand.

An electro-motor I0 if. coupled to an air comform piece.

pressor I I and feeds the air into a collecting tank I2 for the purposeof providing the hood 1 and the cylinders I5 with compressed air. Theconduit from the tank to the hood passes through a heating device I3 asis shown in Fig. 3 and is 5 controlled by a cut off valve I4 and by anonreturn valve 3l preventing an escape of compressed air from the hoodinto the tank. Another valve 22" controls the outlet of the. airenclosed between the pistons I6 and the cut off valve 22. when the hoodhas to be lowered.

Since hood 'I is movable, while tank I2 remains stationary, thecompressed air conduit between 15 the two cannot be rigidly connected.The connection is only established in the operative position. Accordingto Fig. 4 the inlet pipe.30 of the hood lits in the .Working position ofthe hood with a conical fit into the funnel shaped end of 20 thedelivery pipe I 4 of the tank.

According to Fig. 1 the hood possesses also the ordinaryg'safetydevices. These are all arranged lon one of the end faces of the hood, towit, a 'IT-fitting 25 communicating on one side with a 25 ventcontrolled by a cut off valve 25 and on the other side with a safetyvalve 2-8 and a manometer 26 and a thermometer 2T. Also the air tank I2possesses a safety valve not shown.

Besides there are vents 29 provided in the ledge 30 6 for the escape ofthe evaporated humidity of the glue and for the air remaining betweenthe rubber' cloth and work piece.

The press is operated as follows:

The hood 'I having the rubber cloth 8 attached 35 to it by means of thesprings 9 is suspended in the hooks 24. Then the form piece withA theveneer plate put on and having adhesive disposed between them is placedupon the table plate and the hood is lowered vby pushing the hooks 24aside 40 and cautiously opening the air relieve valve 22".' The hood islowered until its edge rests within the grooves of the ledge and pipes30 and I4 have become joined. Now the compressed air collected. in tankI2 and heated in device I3 is admitted by 45 opening the valve I4' andthe pressure inside the hood increased until the veneer plate, softenedby the heat, has been fully applied tightly to the Inv this state .thepress is left until the glue has been hardened. This hardening will 50be accelerated by heating-the table plate 2. After the hardening of theglue the hood is removed again by opening first valve 25 and closingvalve 24' to let escape the pressure Within the hood, whereupon valve22' may be opened to lift off 55 van- 2 I I p 2,151,880

10 vents between it and the plate, a, hood having its edges fitting intosaid ledge, a flexible impermeable cloth held fast between said edgesand the ledge, and means for raising and lowering said hood, said meanscomprising vertical guide rails, fast to the table plate, .guide piecesfitting said guide rails and fast to the hood, vertical pneumaticcylinders open at the top and cooperating pistons with rods attached tosaid guide pieces.

HANS WIEDERKEHR.

